<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    div {
      border: solid;
    }

    .tmb {
      width: 600px;
      height: 400px;
      margin: auto;
      position: relative;
    }

    .tmb .top {
      height: 100px;
      background-color: antiquewhite;
    }

    .tmb .middle {
      background-color: rgb(229, 250, 215);
      position: absolute;
      top: 100px;
      bottom: 100px;
      left: 0;
      right: 0;
    }

    .tmb .bottom {
      height: 100px;
      background-color: antiquewhite;
      position: absolute;
      bottom: 0;
      left: 0;
      right: 0;
    }
  </style>
</head>

<body>
  <div class="tmb">
    <div class="top">上</div>
    <div class="middle">中</div>
    <div class="bottom">下</div>
  </div>

</body>

</html>